Observability Analysis and EKF-Based Sensorless Control of Permanent Magnet Synchronous Machine

The observability analysis is presented and a combining method applying extended Kalman filter (EKF) and high frequency injection (HFI) method is proposed to realize the estimation of rotor speed and position at standstill and in normal situation for permanent magnet synchronous machine (PMSM). Considering the observability of start-up situation, a surface-mounted permanent magnet synchronous machine (SPMSM) model is developed using vector control method, then the high frequency injection methods are carried out to estimate the rotor speed and position accurately at standstill, while the extended Kalman filter algorithm is applied to validate the observability. Simulation results are shown that the proposed method can estimate the rotor position and speed accurately.